Aircraft door with moving hinge line

ABSTRACT

An aircraft door and hinge assembly therefor is mounted in an opening in an airframe, which opening lies at an angle with the horizontal plane of the aircraft. The door is mounted on a hinge assembly which provides first for upwardly inclined movement of the door to disengage it from its stop engagement with the opening in the airframe. Thereafter, the hinge assembly provides for outward movement of the door, displacing the hinge axis of the door from a position in which the axis makes an acute angle with the horizontal plane of the airframe to a position at which the hinge axis is substantially perpendicular to the horizontal plane. The door is mounted or hinged on the hinge assembly at two points. The hinge assembly provides for one of the hinge points to move outwardly from the airframe a greater distance than the other. Thus the hinge axis can be vertically aligned with respect to the airframe. When the hinge axis is vertically positioned the door can swing to an open position away from the opening in the airframe, allowing ingress and egress through the opening.

[ Feb. 12, 1974 i 1 AIRCRAFT DOOR WITH MOVING HINGE LINE [75] Inventor:Irwin G. Baker, Bellevue, Wash.

[73] Assignee: The Boeing Company, Seattle,

Wash.

[22] Filed: Apr. 28, 1972 [21] App]. No.: 248,445

Primary Examiner-Kenneth Downey Attorney, Agent, or Firm-Christensen &Sanborn [57] ABSTRACT An aircraft door and hinge assembly therefor ismounted in an opening in an airframe, which opening lies at an anglewith the horizontal plane of the aircraft. The door is mounted on ahinge assembly which provides first for upwardly inclined movement ofthe door to disengage it from its stop engagement with the opening inthe airframe. Thereafter, the hinge assembly provides for outwardmovement of the door, displacing the hinge axis of the door from aposition in which the axis makes an acute angle with the horizontalplane of the airframe to a position at which the hinge axis issubstantially perpendicular to the horizontal plane. The door is mountedor hinged on the hinge assembly at two points. The hinge assemblyprovides for one of the hinge points to move outwardly from the airframea greater distance than the other. Thus the hinge axis can be verticallyaligned with respect to the airframe. When the hinge axis is verticallypositioned the door can swing to an open position away from the openingin the airframe, allowing ingress and egress through the opening.

18 Claims, 12 Drawing Figures PATENTED FEB I 2 I974 SHEET 1 0? a IAIRCRAFT DOOR WITH MOVING HINGE LINE BACKGROUND OF THE INVENTION Thepresent invention relates to door structures and more particularly to anaircraft door having a movable hinge line.

Prior doors of the type utilized for ingress and egress from apressurized cabin on commercial aircraft require very expensive, complexmechanisms for opening and closing. Suitable aircraft doors of the typein present use normally must open outwardly from the airframe sincespacewithin the cabin interior is at a premium. Furthermore, passengeraircraft doors have been of the type which must seat in or seal with thedoor opening or door frame from the inside (plug type door) to preventblowout of the door from internal cabin pressure at altitude.

One suitable door of the prior art is disclosed in the U. S. Pat. No.3,051,280 to Bergman et al. This door closes with outward movement tofunction as a plug type door. This door is connected to the airframe inthe opening with a complex hinge mechanism which allows the door firstto swing inwardly in the path of the opening, and at the same timecollapses the top and bottom portions of the door so that the door canbe fitted through the opening and swung outwardly of the airframe. Thusfull access through the cabin opening is provided. This door, however,has certain drawbacks in It is an object of the present invention toprovide a door which pressure seals to the airframe on a relativelynoncomplex seal plane, i.e., one that conforms generally to the shape ofthe door rather than having to curve around the hinge mechanism.

It is another object of the invention to prevent inward movement of thedoor hinge assembly from the vertical positioning of the hinge line whenthe door is being rotated to an open position.

SUMMARY OF THE INVENTION The present invention provides in combination ahinge assembly for moving the hinge line of an aircraft door from afirst position in blowout preventing senting engagement with a doorframe structure mounted in aircraft at an angle with the horizontalplane of the aircraft to a second position wherein the hinge line issubstantially vertical for swinging the door open along the said hingeline. The hinge assembly includes a first linkage means for moving afirst point on the door outwardly from the door frame from a closedposition to an open position. One end of the first linkage means isfixedly connected to the door frame while the other end of the firstlinkage means is pivotally connected to a first hinge means on the door.A second linkage means moves a second point on the door outwardly fromthe door frame between a closed position and an open position. Similarto the first linkage means, the second linkage means has one end thatthe mechanism required to operate the door in this fixedly connected tothe door frame while the second manner is relatively complex andrequires-very precise machining and mounting. Due to the nature of thehinge assembly little adjustment can be made to the door once it isinstalled in the aircraft. If the door does not properly seat in thedoor opening when installed, the door must be removed and the hinge linein the opening must be reworked to conform to the door structure. Themanufacturing tolerance levels required to ensure satisfactory mountingof such doors on the airframes are quite high, resulting in highproduction and assembly costs.

I A vari .ty of other doors have been designed as indicated by the priorart in attempts to alleviate some of the manufacturing and assemblytolerance requirements and to reduce the high cost of door assembly.Other doors available in the prior art, however, do not fulfill therequirements of such a door as well as the exemplary door mentionedabove.

It is an object of the present invention to provide a lower costaircraft door which can easily be installed on an airframe and which canbe adjusted in several directions on the airframe to accurately fit thedoor frame and mate with the pressure seals.

It is a further object of the present invention to pro vide a door whichwill operatively seal the opening in the airframe as well as theconventional plug type door, but which does not require substantialinward movement during the opening procedure. It is a further object ofthe present invention to provide an aircraft door which can be easilyinstalled and/or replaced. It is an object of the present invention toprovide an aircraft door which can be mounted in an opening in anairframe which is at an angle with the horizontal. It is a furtherobject of the present invention to provide a door which has a movinghinge line from the door frame angle to the vertical, thus requiring nospring assist to open the door outwardly from the airframe.

end of the linkage means is pivotally connected to a second hinge meanson the door. The first and second hinge means are mounted by saidlinkage means for movement in a vertical plane. When the door is open,the hinge means are alinged such that the hinge axis of the door isvertically oriented.

BRIEF DESCRIPTION OF THE DRAWINGS A better understanding of the presentinvention can be derived from reading the ensuing specification inconjunction with the accompanying drawings wherein:

FIGS. 1 through 4 are pictorial exterior views of the door of thepresent invention mounted in an airframe opening showing the operationalsequence of the door;

FIG. 5 is an isometric view of the door of the present invention in anopen position exposing the linkage mechanism;

FIGS. 6 through 8 are detailed cross-sectional views of the entire doorshowing it, respectively, in a closed position, a partially openposition and a fully open position; and

FIGS. 9 through 12 are detailed cross-sectional views of the lower hingemechanism of the present invention showing the door, respectively, in aclosed position, in two intermediate positions and in a fully openposition.

DESCRIPTION OF PREFERRED EMBODIMENT Referring to FIG. 1, an airframe 10having an outer wall 12 contains a door opening 14, for example to apressurized passenger compartment within the airframe 10. The door ofthe present invention is mounted in the opening 14. In FIG. 1 the dooris shown in a fully closed position. The angle of 13 indicated betweendot-dash lines 18 and 20 is representative of the angle at which manydoors in large commercial aircraft are mounted. This angular mounting isgenerally caused by the fact that the door openis generally used aspassenger compartment space,

whereas the lower half of the airframe 10 is utilized for cargo.

The door 16 of the present invention can of course be mounted formovement to a vertical position indicated by dot-dash line 20 either inthe lower half of the fuselage or in the upper half of the fuselage. Thepresent invention, however, is most efficacious for mounting in theupper half of the fuselage for ingress and egress through an opening tothe pressurized passenger compartment, since it alleviates the necessityof opening the door upwardly against gravity and thus eliminates therequirement for a spring assist.

As shown in FIG. 2 latch arm 22 has been pulled upwardly. The latch arm22 actuates mechanism (shown later) which lifts the door 16 upwardly inthe direction of arrow 24. This movement disengages the door from stopslocated in the opening 14. The hinge mechanism, generally designated 26in these figures, allows the door to move outwardly in the direction ofarrows 28 and 30 (FIG. 3). The upper portion of the door 16 movesoutwardly in the direction of arrow 28 a greater distance than the lowerportion of the door as indicated by arrow 30. As indicated by dot-dashline 20, the hinge line of door 16 is now perpendicular to thehorizontal plane of the airframe, i.e., generally vertical.

After the door 16 has been moved to its vertical position, it can berotated through 180 indicated by arrow 32 in FIG. 4 to a fully openposition. The hinge mechanism 26 completely removes the door 16 from theregion of ingress and egress through opening 14. Furthermore, the actionof the door 16 does not require any substantial inward movement insidethe airframe 10. Furthermore, the door can be easily opened withoutpower assist from the inside or outside, since the hinge line of thedoor has been moved to a vertical position from the angular closedposition.

Referring to FIG. 5, an enlarged isometric view of the door andoperative latch mechanism is shown. The upper hinge assembly, generallydesignated 40, includes a fixed link 42 attached to a side structuralmember 48 of the door frame. The structural member 48 can be part of thestructure of airframe 10. A main crank 44 is pivotally connected by pin46 to the fixed link 42. A control link 50 is also pivotally mounted bypin 52 to the fixed link 42 a spaced distance above the main crank 44. Aconnecting link 54 is pivotally attached to control link 50 by pivot pin56 and to main crank 44 by pivot pin 58. Connecting link 54 is alsopivotally connected to bearing 60 by pivot pin 62. Bearing 60 is mountedso that hinge rod 64 is rotatable within bearing 60 and so that it isalso vertically slidable therein. Hinge rod 64 is attached to the doorpanel 36 by bracket 66 at its upper end and by bracket 68 at its lowerend.

The lower hinge assembly, generally designated 70, also includes a fixedlink 72 which is mounted to side frame structural member 48. Assembly 70further includes a main crank 74 pivotally attached by pivot pin 76 tofixed link 72. Control link 78 is also pivotally connected to fixed link72 by pivot pin 80. Connecting link 82 is pivotally connected at its oneend to control link 78 by pivot pin 84 and to main crank 74 by pivot pin86. When the door is in the open position, latch member 88 engages anextension of the main crank 74 to prevent backward movement of the doorduring the time that it is in the open or partially open position asshown in FIG. 5. Latch member 88 is pivotally mounted on connecting link82 by pivot pin 90. Connecting link 82 is pivotally connected at itsother end by pivot pin 92 to a bearing 94. The bearing 94 is mounted forvertical sliding movement and rotational movement on hinge rod 96 whichin turn is mounted on door panel 36 by brackets 98 and 100. When thedoor is rotated about the hinge rods 64 and 96 to a vertical but closedposition the pin 89 on latch member 88 engages plate 91 to disengagelatch 88 from the main crank 74. Thus the lower hinge assembly can moveabout its various pivot points to draw the door into the opening 14.

The upper hinge assembly 40 is interconnected with the lower hingeassembly 70 by means of a first connecting link 102 attached to bellcrank 104 which is in turn attached to connecting link 106. Connectinglink 106 is in turn connected to an arm of main crank 74 (not shown inthis view). Bell crank 104 is pivotally mounted in a mounting plate 108by pin 110. A coiled torsion spring mounted within housing 112 andattached to torsion rod 114 is connected by linkage 116 to the mountingplate 108. The spring through coaction with linkage 116 biases the doorin the open position shown.

The door 16 is held in a slightly vertically raised position asindicated in FIG. 2 throughout the remaining operational steps as shownin FIGS. 3 and 4. This is accomplished by a mechanism which will bedescribed in detail with respect to the remaining figures. However, itshould be noted at this point that a lower guide track 120 is providedfor and mounted securely to structural member 48. The follower 122mounted for rotation on structural member 124 of the door mates with thetrack 120 as the door is being closed. A similar track 126 is mounted tothe upper portion of structural member 48 on the door frame. Similarly afollower 128 mounted for rotation on structural member 130 of the doormates with the track 126 as the door is being closed. Likewise a camtrack 132 is mounted on structural member 48 of the door frame. A roller134, mounted on crank 136, is in turn securely mounted to torque tube138. As the door is being closed the roller 134 mates with the upperportion of the track 132. As the followers 128 and 122 mate with thedownwardly directed portion of tracks 126 and 120, respectively, thecrank 136 is rotated by actuating lever arm 140 connected to torque tube138. Thus the roller 134 traverses the inward portion of cam track 132,pulling the door inwardly. As the roller 134 traverses the inward andlower portion of cam track 132, the door is pulled inwardly anddownwardly. The followers 122 and 128 simultaneously engage first theoutwardly directed portions of the tracks 120 and 126 and secondly thedownwardly directed portions of tracks 126 and 120. Thus the door issecurely affixed to and aligned with the door opening 14. This operationwill be explained in greater detail in relation to later figures.

Another crank member 142 is also securely attached to torque tube 138. Aconnecting link 144 is pivotally connected between crank 142 and arm146. Arm 146 is pivotally connected to bracket 148, which is in turnconnected to the door structure. When the door is in a closed positionit will be seen that the coaction of crank 142, connecting link, 144'and arm 146 will cause the arm 146 to. rise to a vertical position. Inthe vertical position a mating surface 150 on arm 146 will mate with astop 152 (not shown in figure but shown in FIG. 6) providedon theinterior side of wall 12.

It also should be noted at this point that the mirror image duplicatesof guide tracks 120 and 126 and of cam track 132 are mounted on anopposing side structure, similar to 48, on the opposite side of theopening 14. Rollers and followers similar to 122, 128 and 134 also areappropriately positioned on the other side of the door 16. For example,crank 154 is connected to the opposite end of torque tube 138 from crank136. Roller 156 mates with the mirror image of cam track 132 mounted onthe opposing side of the door frame.

Referring now to FIG. 6 a cross-sectional view of the door assemblytaken along the left-hand edge thereof is shown. The door 16 is shown ina closed position within the opening 14. As can be seen the followers122 and 128 engage the lower portions of tracks 120 and 126. The camroller 134 is positioned in the lower forward portion of the cam track132. The torque tube 138 is shown in cross section while lever arm 140is shown in ghost outline. The upper hinge assembly 40 and the lowerhinge assembly '70 are shown in their retracted positions.

As shown in FIG. 7, the lever arm 140 connected to torque tube 138 hasbeen rotated upwardly in the direction of arrow 160. This, of course,will cause torque tube 138 to be rotated in the same manner. The roller134 has traversed the upwardly directed portion of cam track 132 thuscausing the door to rise upwardly out of the lower portion of guidetracks 120 and 126. The door is allowed to move upwardly on the hingelinkages 40 and 70 via the respective sliding bearings 60 and 94 whichare slidably mounted on hinge rods 64 and 96. As shown, the door hasbeen partially translated outwardly along its moving hinge line.

As the door is pushed further outwardly in the direction of arrow 162-,FIG. 8, the hinge linkage mechanisms 40 and 70 are extended to the fullopen position. It will be noted that the hinge axis of the bearings 60and 94 are now vertically aligned along dash-dot line 20. Thus the doorassembly 16 can be rotated about the hinge axis (line to the full openposition as shown in FIG. 8.

The coil spring 164 within housing 112 is wound in torsion and connectedto torsion rod 114. Torsion rod 114 is in turn connected by links 166and 168 to the mounting plate 108 connected to structural member 48 onthe door frame. The coil spring 164 is wound in torsion such that thedoor 16 is biased in the open position shown in FIG. 8. When the door isclosed it can be seen in FIG. 6 that the links 166 and 168 will foldalong the side of plate 108 in a retracted position.

The linkage connecting the hinge assemblies 40 and 70 is better seen inthis view. It includes connecting link 102 connected to a second arm 170of main crank 44. Connecting link 102 is also pivotally connected tobell crank 104 which in turn is pivotally mounted by pivot pin 110 onplate 108. The other arm of bell crank 104 is pivotally connected toconnecting link 106 which is in turn pivotally connected at its otherend to a second arm 174 of main crank 74 of the lower hinge assembly 70.

Connecting link 102, and if desired connecting link 106, includes aright-hand threaded upper portion 176 and a lower left-hand threadedportion 178. These two portions threadably engage a central portion 180of the connecting link 102. When the central portion 180 of connectinglink 102 is rotated in one direction the total length of the connectinglink 102 will be increased. This will cause the main link 44 to moveupwardly and thus bring the upper portion of door 16 toward the opening14 in the airframe wall 12. Likewise when the central portion 180 oflink 102 is rotated in the opposite direction the total length ofconnecting link 1112 is decreased. When the length is decreased theconnecting link 44 will be rotated downwardly, thus increasing thedistance from the top portion of door 16 to the opening 14 in theairframe 12. Thus angular adjustment is provided for the door 16 by thepresent invention. Through these adjustments the door can be positionedfor proper alignment with guide tracks and 126 and can be properlyregistered in the opening 14 at any time, not only at the time ofinitial installation but when any future adjustment is required.

As shown in FIG. 6, it will be noted at this time that the portions ofguide tracks 120 and 126 (into which the guide followers 122 and 128 arepositioned when the door is in a closed position) are angled slightlybackwardly from the rest position of the followers 120 and 128. Thisangle, for example on the order of 3 from the pressure plane of thedoor, provides a positive lock for the door preventing blowout of thedoor by internal cabin pressure. The pressure plane can be defined as animaginary plane from upper edge of opening 14 to the lower edge ofopening 14 against which inter nal cabin pressures act in a normaldirection. In addition to this feature of the invention, a top latchmember is provided, including arm 146, mating surface and stop 152mounted on the exterior skin of wall 12. The mating surface 150 incoation with stop 152 prevents both upward and outer movement of thedoor. This mechanism thus provides a positive latching for the door onceit is in the closed position and the lever arm 140 brought to its closedposition.

A seal member 184 is shown at the upper portion of the opening 14attached to bracket 186 in turn attached to the outer skin of wall 12.Seal 184 runs along the top of the opening 14 as well as along the sidesthereof. A similar seal 188 is shown at the bottom of the door 16. Seal188 extends along the bottom of the door 16. A suitable seal transfersurface is provided at the lower corners of the door 16 where the seals184 and 188 meet. Thus seals 184 and 188 surround the periphery of theopening 14 to provide air tight seal between the passenger compartmentand the exterior of the airframe 10.

Referring now to FIGS. 9 through 12, the lower hinge assembly 70 isshown in enlarged detail. In FIG. 9 the door 16 is shown in a completelyclosed position, thus follower 122 rests at the bottom of track 120. Astop 190 is pivotally attached by pivot pin 192 to bracket 194 on thedoor panel 36. A small spring 196 biases the stop 190 in the directionof arrow 198. However, the stop 190 is prevented from moving in thedirection of arrow 198 by adjustable pin 200 which engages a surface ofconnecting link 82 of hinge assembly '70.

As shown in FIG. 10, as the door is moved upwardly the hinge linkage 70remains substantially stationary. The stop 190 rises with the door asbearing 94 moves upwardly on hinge rod 96. The bottom end of stop 190rises above a thrust bearing 202 attached to the top of bearing 94. Asthe door moves outwardly as in FIG. 11 and follower 122 leaves the upperportion 204 of the guide track 120 and simultaneously pin 200 disengagesfrom the side of connecting link 82, thus allowing the stop 190 to movein the direction of arrow 198 onto thrust bearing 202. As the follower122 leaves the top portion 204 of guide track 120, the entire weight ofthe door is transmitted through stop 190 to thrust bearing 202 and thusto the bearing 94 and connecting linkage 82. The door 16 is held in itsraised position by the stop 190 for the traverse out to a position wherethe hinge axis is vertically positioned.

As the door is swung 180 to an open position as shown in FIG. 12 thethrust bearing 202 remains stationary but allows the door to rotateabout bearing 94 (and its upper hinge assembly counterpart bearing 60).When the door 16 is returned to a closed position, the oppositeprocedure occurs. As shown in FIG. 11, when follower 122 begins toengage the upper portion 204 of the guide track 120, stop 190 is pushedbackwardly by contact with connecting link 82. Thus the weight of thedoor is transferred to follower 122 and the upper portion 204 of track120. Likewise, the door is allowed to drop into the lower portion oftrack 120 without interference from stop 190.

When the door 16 is in an unrotated position, as shown in FIGS. 9through 11, the pin 89 on latch member 88 engages the plate 91 (FIGS.and 12) on a structural member of the door 16. Latch member 88 islikewise biased by a small spring 206 in a direction toward the viewerin FIG. 9. When the door is swung open as shown in FIG. 12, pin 89disengages from the plate 91. This allows the latch member 88 to pivotin the direction of the viewer to lockably engage the inward side 208 ofmain crank 74 of lower hinge assembly 70. Thus when the door is in therotational open position as shown in FIG. 12 the lower hinge linkageassembly 70 cannot retract to a closed position, preventing the door 16from being pushed inwardly against the outer skin 12 of the airframe 10.When the door is closed, plate 91 again engages the pin 89 to releasethe latch member 88 from the back surface 208 of main link 74. Thus asthe door is pulled inwardly hinge mechanism 70 can return to a retractedposition.

The present invention has been described in relation to a preferredembodiment. It is to be understood that those of ordinary skill in theart can make various changes, alterations and substitutions ofequivalents without altering the original concepts of the invention. Itis intended that the invention be limited only by the definitioncontained in the appended claims.

What is claimed is:

l. A hinge assembly for a door for mounting in an opening in an airframecomprising:

first and second hinge linkage means for connecting said door to saidairframe, each of said hinge linkage means comprising a fixed linkhaving means thereon for attachment to said airframe, a main crankpivotally connected to said fixed link, a control crank pivotallyconnected to said fixed link, and a connecting link pivotally connectedto said main crank and to said control crank, one end of said connectinglink extending beyond the pivotal connection to said main crank, saidpivotal connections of said hinge linkage means being parallel to eachother,

a bearing means pivotally attached to said one end of 6 said connectinglink on each of said linkage means, each of said bearing means beingpivotally attached to said door at a spaced distance from each other todefine a hinge axis for said door, said hinge linkage means adapted tomove one of said bearing means through a path of greater distance thanthe path of the other of said bearing means, and

5 means for securing said door in a closed position in said opening.

2. The assembly of claim I further comprising:

means interconnecting a crank on each of said hinge linkages forproviding for differential movement between said linkages to move saidhinge axis into a substantially vertical position.

3. The assembly of claim 2 wherein said means interconnecting a crank isadjustable to provide variable relative positioning between said hingelinkages.

' 4. The assembly of claim 2 further comprising:

a pair of bar means mounted substantially vertically on said door whensaid door is in an open position, said bar means mounted a spaceddistance from each other, each of said bearing members slidably andpivotally attached to one of said bar means.

5. The assembly of claim 2 wherein said means for securing said doorcomprises:

a first pair of track means for mounting on opposing sides of saidairframe, each of said track means including a track with an inwardlyextending portion and a downwardly extending portion,

said door having a pair of mating follower means mounted on each sidethereof capable of engaging the tracks in said track members,

lever means for lifting said door out of the downwardly extendingportion of said tracks when said door is in a closed position.

6. The assembly of claim 5 wherein said lever means comprises:

a cam track means having a cam surface mounted on the body frame, saidcam surface including a first outwardly extending portion, an upwardlyextending portion and a second outwardly extending portion, saidportions forming a smooth arcuate cam surface, bar rotatably mountedhorizontally in said door, and hand manipulable means attached theretofor rotating said bar, cam follower means including a crank attached tosaid bar and a cam follower on one end thereof for mating with said camtrack means said cam follower means holding said door in a down andclosed position when engaging said first outwardly extending portion ofsaid cam track means, said cam follower means lifting said door out ofthe downwardly extending portion of said first track means when engagingsaid upwardly and second outwardly extending portions of said cam trackmeans.

7. The assembly of claim 6 further comprising:

stop means on said door engaging at least one of said bearings forpreventing downward movement of said door as it disengages upwardly fromsaid first track means,

means for disengaging said stop means when said mating follower meansengages said first track means.

8. The assembly of claim 5 further comprising:

a second pair of track means mounted on opposing sides of said doorframe, said second pair of track means similar to said first pair, saidsecond pair mounted near the upper sides of said frame, said first pairmounted near the lower sides of said frame.

9. The assembly of claim 2 further comprising:

spring means for biasing said door toward a first position about thepivotal axis on said bearing members.

10. The assembly of claim 6 further comprising:

a stop mounted on the lintel of said frame,

means actuated by said bar for engaging said stop when said door is in aclosed position and for disengaging said stop when said cam followermeans is actuated.

11. The assembly of claim 2 wherein said main crank on each of saidhinge linkages comprises a bell crank, one arm of said bell crank beingpivotally attached to said connecting link, and wherein said meansinterconnecting a crank on each of said hinge linkages comprises:

a first interconnecting link pivotally attached to each of the free endsof said main bell cranks, the ends of said interconnecting linkpivotally connected to the arms of a third bell crank, the primary axisof the third bell crank being pivotally attached to said door frame at aposition fixed relative to the fixed links on each of said hinge linkagemeans.

12. In combination, a hinge assembly for moving the hinge line of anaircraft door from a first position in blowout preventing seatingengagement with a door frame structure mounted in an aircraft at anangle with the horizontal plane of the aircraft to a second positionwherein the hinge line is substantially vertical for swinging said dooropen along said hinge line comprismg:

first linkage means for moving a first point on said door outwardly fromsaid door frame, said first linkage means movable between a first closedposition and a second open position, one end of said first linkage meansfixedly connected to said door frame, the second end of said linkagemeans pivotally connected to a first hinge means on said door,

second linkage means for moving a second point on said door outwardlyfrom said door frame, said second linkage means movable between a firstand second position, one end of said linkage means fixedly connected tosaid door frame, the second end of said linkage means pivotallyconnected to a second hinge means on said door, said first and secondhinge means mounted on said door in a vertical plane and spaced fromeach other.

13. The combination of claim 12 further comprising:

means interconnecting said first and second linkage means for providingdifferential outward movement between said first and second linkagemeans.

14. The combination of claim 13 wherein said first and second hingemeans mounted for sliding movement on said door, the combination furthercomprising:

guide means mounted on said door frame and guided means mounted on saiddoor, said guide and guided means coacting to guide said door from aclosed position to a vertically displaced position, said linkage meansadapted to follow said door to said vertically displaced position,

stop means coacting with said linkage means for holding said door insaid vertically displaced posi tion as said door moves from saidvertically displaced position to said second position.

15. The combination of claim 14 further comprising: means acting whensaid door is in said second position to bias said door toward an openposition. 16. The combination of claim 15 further comprising: handactuatable means connected to said door and coacting with means mountedon said door frame to lift said door from said first position to saidvertically displaced position. 17. The combination of claim 15 furthercomprising: lock means responsive to said hand actuatable means forengagement and disengagement for securing said door in said firstposition in said door frame.

, 18. The combination of claim 14 further comprising:

means associated with said door and at least one of said hinge means forpreventing inward movement of said hinge means when said door is in saidsecond position and is in a rotational position on said hinge axis.

1. A hinge assembly for a door for mounting in an opening in an airframe comprising: first and second hinge linkage means for connecting said door to said airframe, each of said hinge linkage means comprising a fixed link having means thereon for attachment to said airframe, a main crank pivotally connected to said fixed link, a control crank pivotally connected to said fixed link, and a connecting link pivotally connected to said main crank and to said control crank, one end of said connecting link extending beyond the pivotal connection to said main crank, said pivotal connections of said hinge linkage means being parallel to each other, a bearing means pivotally attached to said one end of said connecting link on each of said linkage means, each of said bearing means being pivotally attached to said door at a spaced distance from each other to define a hinge axis for said door, said hinge linkage means adapted to move one of said bearing means through a path of greater distance than the path of the other of said bearing means, and means for securing said door in a closed position in said opening.
 2. The assembly of claim 1 further comprising: means interconnecting a crank on each of said hinge linkages for providing for differential movement between said linkages to move said hinge axis into a substantially vertical position.
 3. The assembly of claim 2 wherein said means interconnecting a crank is adjustable to provide variable relative positioning between said hinge linkages.
 4. The assembly of claim 2 further comprising: a pair of bar means mounted substantially vertically on said door when said door is in an open position, said bar means mounted a spaced distance from each other, each of said bearing members slidably and pivotally attached to one of said bar means.
 5. The assembly of claim 2 wherein said means for securing said door comprises: a first pair of track means for mounting on opposing sides of said airframe, each of said track means including a track with an inwardly extending portion and a downwardly extending portion, said door having a pair of mating follower means mounted on each side thereof capable of engaging the tracks in said track members, lever means for lifting said door out of the downwardly extending portion of said tracks when said door is in a closed position.
 6. The assembly of claim 5 wherein said lever means comprises: a cam track means having a cam surface mounted on the body frame, said cam surface including a first outwardly extending portion, an upwardly extending portion and a second outwardly extending portion, said portions forming a smooth arcuate cam surface, a bar rotatably mounted horizontally in said door, and hand manipulable means attached thereto for rotating said bar, cam follower means including a crank attached to said bar and a cam follower on one end thereof for mating with said cam track means said cam follower means holding said door in a down and closed position when engaging said first outwardly extending portion of said cam track means, said cam follower means lifting said door out of the downwardly extending portion of said first track means when engaging said upwardly and second outwardly extending portions of said cam track means.
 7. The assembly of claim 6 further comprising: stop means on said door engaging at least one of said bearings for preventing downward movement of said door as it disengages upwardly from said first track means, means for disengaging said stop means when said mating follower means engages said first track means.
 8. The assembly of claim 5 further comprising: a second pair of track means mounted on opposing sides of said door frame, said second pair of track means similar to said first pair, said second pair mounted near the upper sides of said frame, said first pair mounted near the lower sides of said frame.
 9. The assembly of claim 2 further comprising: spring means for biasing said door toward a first position about the pivotal axis on said bearing members.
 10. The assembly of claim 6 further comprising: a stop mounted on the lintel of said frame, means actuated by said bar for engaging said stop when said door is in a closed position and for disengaging said stop when said cam follower means is actuated.
 11. The assembly of claim 2 wherein said main crank on each of said hinge linkages comprises a bell crank, one arm of said bell crank being pivotally attached to said connecting link, and wherein said means interconnecting a crank on each of said hinge linkages comprises: a first interconnecting link pivotally attached to each of the free ends of said main bell cranks, the ends of said interconnecting link pivotally connected to the arms of a third bell crank, the primary axis of the third bell crank being pivotally attached to said door frame at a position fixed relative to the fixed links on each of said hinge linkage means.
 12. In combination, a hinge assembly for moving the hinge line of an aircraft door from a first position in blowout preventing seating engagement with a door frame structure mounted in an aircraft at an angle with the horizontal plane of the aircraft to a second position wherein the hinge line is substantially vertical for swinging said door open along said hinge line comprising: first linkage means for moving a first point on said door outwardly from said door frame, said first linkage means movable between a first closed position and a second open position, one end of said first linkage means fixedly connected to said door frame, the second end of said linkage means pivotally connected to a first hinge means on said door, second linkage means for moving a second point on said door outwardly from said door frame, said second linkage means movable between a first and second position, one end of said linkage means fixedly connected to said door frame, the second end of said linkage means pivotally connected to a second hinge means on said door, said first and second hinge means mounted on said door in a vertical plane and spaced from each other.
 13. The combination of claim 12 further comprising: means interconnecting said first and second linkage means for providing differential outward movement between said first and second linkage means.
 14. The combination of claim 13 wherein said first and second hinge means mounted for sliding movement on said door, the combination further comprising: guide means mounted on said door frame and guided means mounted on said door, said guide and guided means coacting to guide said door from a closed position to a vertically displaced position, said linkage means adapted to follow said door to said vertically displaced position, stop means coacting with said linkage means for holding said door in said vertically displaced position as said door moves from said vertically displaced position to said second position.
 15. The combination of claim 14 further comprising: means acting when said door is in said second position to bias said door toward an open position.
 16. The combination of claim 15 further comprising: hand actuatable means connected to said dOor and coacting with means mounted on said door frame to lift said door from said first position to said vertically displaced position.
 17. The combination of claim 15 further comprising: lock means responsive to said hand actuatable means for engagement and disengagement for securing said door in said first position in said door frame.
 18. The combination of claim 14 further comprising: means associated with said door and at least one of said hinge means for preventing inward movement of said hinge means when said door is in said second position and is in a rotational position on said hinge axis. 